I started here: https://github.com/metal-by-example/metal-spatial-rendering

Hi Muse, I have tracked it down to this block. Cheers. extension LayerRenderer.Clock.Instant { func toTimeInterval() -> TimeInterval { let duration = LayerRenderer.Clock.Instant.epoch.duration(to: self) let secondsPart = Double(duration.components.seconds) let attosecondsPart = Double(duration.components.attoseconds) / 1e18 return secondsPart + attosecondsPart } }